A series of CaO-based sorbents were synthesized through a sol-gel method and doped with different amounts of CeO2. The sorbent with a Ca/Ce molar ratio of 15:1 showed an excellent absorption capacity (0.59 gCO2/g sorbent) and a remarkable cycle durability (up to 18 cycles). The admirable capture performance of CaCe-15 was ascribed to its special morphology formed by the doping of CeO2 and the well-distributed CeO2 particles. The sorbents doped with CeO2 possessed a loose shell-connected cross-linking structure, which was beneficial for the contact between CaO and CO2. CaO and CeO2 were dispersed homogeneously, and the existence of CeO2 also decreased the grain size of CaO. The well-dispersed CeO2, which could act as a barrier, effectively prevented the CaO crystallite from growing and sintering, thus the sorbent exhibited outstanding stability. The doping of CeO2 also improved the carbonation rate of the sorbent, resulting in a high capacity in a short period of time.

In this paper, we report the development of synthetic CaO-based sorbents via a fast precipitation method with the assistance of sodium poly(styrenesulfonate) (PSS). The effect of PSS on physical properties of the CaO sorbents and their CO2 capture performance were investigated. The presence of PSS dispersed the CaO particles effectively as well as increased their specific surface area and pore volume remarkably. The obtained porous spherical structure facilitated CO2 to diffuse and react with inner CaO effectively, resulting in a significant improvement in initial CO2 carbonation capacity. A proper amount of Mg(2+) precursor solution was doped during a fast precipitation process to gain CaO-based sorbents with a high anti-sintering property, which maintained the porous spherical structure with the high specific surface area. CaO-based sorbents derived from a MgxCa1-xCO3 precursor existed in the form of CaO and MgO. The homogeneous distribution of MgO in the CaO-based sorbents effectively prevented the CaO crystallite from growing and sintering, further resulting in the favorable long-term durability with carbonation capacity of about 52.0% after 30 carbonation/calcination cycles.

The contact angles of the aqueous solution of ethanol and that of n-propanol on copper, aluminum, and stainless steel surfaces are reported. The contact angles were measured under atmospheric conditions, and then under vapor-liquid equilibrium conditions at 1 atm and different temperatures. The results showed the variations of the contact angles with the concentrations of aqueous solutions on different metal material surfaces with different roughness. Some unstable behavior of the wetting ability around the azeotropic point of a binary solution is reported. Influences of concentration, kind of materials, and the surface roughness on the wetting ability are discussed. The model for predicting the contact angle of alcohol aqueous solutions on metal surfaces under atmospheric and vaporliquid two-phase equilibrium conditions at 1 atm is derived from the Young equation.